Journal of Applied Science & Process Engineering

Modelling and Analysis of Salient-Pole Rotor Interior Permanent Magnet Synchronous Motor for Oil and Gas Pump Applications

2023-10-31T09:47:22+00:00

This paper presents the design and dynamic simulation of a line-start, three-phase Interior Permanent Magnet Synchronous Motor (IPMSM) intended for pump applications in the oil and gas industry. The problem addressed in this paper pertains to the replacement of an existing induction motor (IM) in an oil and gas pump station with a more efficient and controllable solution, the IPMSM since IMs are known to be less efficient and IPMSM is easier to control. The chosen motor type employs a traditional salient-pole rotor with cage windings, known for its line-start capability, making it a feasible choice for constant-speed and pump applications. The dynamic simulation of the proposed IPMSM is carried out using MATLAB/Simulink, focusing on fundamental harmonic analysis in direct-phase variables. The results demonstrate rapid startup to synchronous speed with minor deviations effectively dampened by the rotor's damper windings. Torque characteristics exhibit some pulsations caused by magneto-motive force (MMF) harmonics; a phenomenon captured by Finite Element Analysis (FEA). The performance results show that the proposed IPMSM with a salient-pole rotor is viable and a promising replacement for induction motors in oil and gas pump stations.

Optimisation of Electrical Discharge Machining Processing for AZ91 Magnesium Alloy using Coupled AHP-Taguchi Analyses-GA Method with the Rank Selection Approach

2023-10-31T09:47:01+00:00

Despite being contemporary, the wire electrical discharge machining (EDM) industry is burdened with complicated and challenging problems. However, the double optimisation method involving Taguchi analyses and genetic algorithms is a powerful tool to help tackle some of these problems. This article evaluates the wire EDM process through a rank-based genetic algorithm coupled with the AHP-Taguchi analyses using the AZ91 magnesium alloy for the first time in the literature. The rank selection method was used at the selection stage of the operations. Six parameters, namely pulse on time, pulse off time, wire feed, wire tension, pulse current and gap voltage, were the process parameters. For all the methods, the total values were computed and compared for the selection, cross-over and mutation operations. It was found that the total values at the selection stage for each of the methods, namely AHP-Taguchi-GA, AHP-Taguchi-Pareto-GA and AHP-Taguchi-ABC-GA methods, were 2750, 4176 and 6306 (best value as Part A), respectively. For all the methods, there was a 25.35% improvement in total value at the cross-over stage compared with the selection stage. The improvement in the total values of the mutation over cross-over and mutation over selection was 53.84% and 92.84%, respectively. These improvement values were for the AHP-Taguchi-GA method but also turned out to be the same for the AHP-Taguchi-Pareto-GA and AHP-Taguchi-ABC methods. The principal advantage of the rank selection method introduced in the present study is to avoid quick convergence. This article is beneficial to the process engineers aimed at improving the wire electrical discharge machining process.

Review of the Approach to Modelling Pesticides Dispersion in Environment for Determining the Concentrations to Which Organisms are Exposed as Part of Risk Assessment

2023-10-31T09:46:39+00:00

There is an interest in the toxicity of pesticides in plant protection treatments for humans and the environment. As such, assessing toxicity risk is essential. Risk assessment is constrained due to the large amount of data to be measured, short collection times, insufficient data even when available, and the absence of bioaccumulation of the pollutant in the target organism. Modelling becomes an ally in overcoming these shortcomings. The assessor thus has at his disposal statistical, compartmental, Gaussian, Lagrangian, and Eulerian models to estimate the exposure of target organisms.

Manufacturing of Poly-DL-Lactic Acid Nanosheets and Evaluation of Tribological Characteristics between Nanosheet Surfaces and Fingers

2023-10-31T09:46:18+00:00

Attention is focused on ultra-thin polymer films (nanosheets) that have high flexibility and adhesiveness and their thickness can be controlled to several tens of nanometers. These nanosheets can be neatly attached to surfaces with complex irregularities without the use of adhesives. Therefore, the ratio of surface area to thickness is very large, and we believe that the relationship with friction is very significant in nanosheet technology for biomedical applications such as wearable devices and wound dressings. The purpose of this study is to investigate the contact mechanism of nanosheets with human fingertip skin in terms of friction coefficient by using the microgravure printing method, which enables thin film coating. From the results of film thickness measurements, it was found that nanosheets of any thickness can be fabricated by the microgravure printing method. The friction measurement results showed that the coefficient of friction of the nanosheets decreased except for vertical loads above F_z=2N. The coefficient of friction increased as the contact area increased. It was found to increase with increasing vertical load under the immersion in water conditions, and conversely, it decreased under the drying condition except for the high normal load of 2N. Furthermore, the coefficient of friction was found to increase with increasing nanosheet thickness. Observation of wear traces showed that when the vertical load was sufficiently high (F_z = 2 N), wear traces containing oily traces such as sebum and sweat appeared on the nanosheet surface. This is thought to function as a lubricant. Polymer nanosheets are a new material, and there have been few studies on friction with this material. Research on friction is very important because polymer nanosheets are expected to be applied to wound dressings and displays of electronic devices.

Quantitative Analysis of the Impact of Climate Change and Human Activities on Runoff Variation in Akwa Ibom State, Nigeria

2023-10-31T09:45:57+00:00

The non-parametric Mann-Kendall (MK) trend test, including the Sen's slope test and Pettitt's test, was used to determine trends, magnitudes, and change points in hydro-meteorological variables from 1972 to 2021. The slope change ratio of accumulative quantity (SCRAQ) method was then used to calculate the relative contributions of climate change and human activities to runoff variation in the Uyo-Itu river basin. Annual rainfall, maximum temperature, minimum temperature, and runoff showed significant increasing trends, whereas annual relative humidity, solar radiation, and potential evapotranspiration showed significant decreasing trends. Between 1992 and 2010, there were abrupt changes in hydro-meteorological variables. However, the runoff shift occurred in 2003. The time period under consideration was divided into two parts: baseline period A and change (impacted) period B. Climate change dominates runoff variation in period B, accounting for 103.6 percent of the variation, while human activities have a negative impact (-3.6%). The results indicate that climate change is the primary driver of runoff variation and that its impact is becoming more severe. Furthermore, the Budyko hypothesis was used to validate the contributions of human activities and climatic changes based on the SCRAQ method. The results showed that the contributions of human activities and climatic changes computed using the SCRAQ method are comparable with those computed using the sensitivity-based method. From this study, it can be concluded that assessing the influence of climate changes and human activities on variations and identifying the major driving forces causing the variations are critical for more efficient water resources management for sustainable economic growth

Effect of Ethrel as a Flower Induction Agent on the Growth and Quality of Fresh Golden Pineapple (MD2) in Malaysia

2023-10-31T09:45:36+00:00

Ethrel was proposed as a good flowering agent to induce the flowering of various fresh pineapples. However, very limited research studies have been carried out on the effect of this inducing agent on the growth of the golden pineapple or Millie Dillard (MD2) in Malaysia, with none in Sarawak. To address this research gap, this study aims to investigate the effect of ethrel on the growth and fruit quality of MD2 pineapples growth in Miri, Sarawak. In this study, ethrel acts as an induction agent that was applied to induce the pineapples at maturity around 11 months after planting (MAP). Moreover, these induced pineapples were harvested 15 MAPs, whereas no pineapples were available for harvesting from the control group that was induced by natural flowering. These results showed that ethrel provided a higher yield in the number of pineapples compared to natural flowering, classifying them as Grade B pineapples. For the growth and fruit quality of the MD2 pineapples, it was found that the average values for the total soluble solids (TSS), total titratable acidity (TTA), pH, diameter, height with a crown, and whole fruit fresh weights with the crown of the pineapples were 16.48 Brix, 0.54 %, pH 3.89, 11.7 cm, 40.3 cm, and 1.4 kg, respectively. Furthermore, the average TSS to TTA ratio was 32.52, which was within the range of 5.5 to 66.4, indicating that the pineapples were sweet with prospects for commercial selling. Hence, it can be concluded that using ethrel as an induction agent is significant in Malaysia.

The Effect of Chemical Treated Okra Waste for Heavy Metal Adsorption from Natural Gas Production Wastewater

2023-10-31T09:45:15+00:00

Nowadays, one of the leading environmental pollutants is heavy metals. Hence, heavy metals in wastewater must be removed before discharge because they are toxic even at low concentrations. This research aims to evaluate the efficiency of okra waste as an adsorbent for heavy metals removal from wastewater in natural gas production. In this study, chemical activation of okra adsorbent was processed to increase the surface area of okra adsorbent for better adsorption, whenever the impregnation of the powdered okra waste was performed using phosphoric acid (H₃PO₄) as the impregnating agent. The okra powder was impregnated at a rate of 4: 1 (v / m). The FTIR was used to characterize the okra-activated carbon and the peaks showed the presence of functional groups such as Hydroxyl (OH), Amino (N-H), Carboxyl (C=O, C-O-C), C-0 stretching and M-O at 3390.05, 2905.5, 1640-1658, 1050.05 and 650 stretching bands respectively. Furthermore, the batch adsorption experiments were conducted via varying agitation speed, contact time, adsorbent dose and adsorbent particle sizes. The results showed that the maximum removal percent of Cd²⁺, Cu²⁺, Pb²⁺, Zn ²⁺, Ag²⁺ and Ba²⁺metal ions had been observed to be at an agitation speed of 1000 rpm, contact time of 90 min, okra adsorbent dose of 0.25 g and particle size of 1.00mm. The experimental findings show that okra wastes from agricultural by-products may be a low-cost adsorbent for future research to remove additional heavy metals owing to their high effectiveness in removing Cd²⁺, Cu²⁺, Pb²⁺, and Zn²⁺ ions from wastewater.